Southbend Marathoner manual Troubleshooting Guide, Table continues on next page

TROUBLESHOOTING

TROUBLESHOOTING MARATHONER GOLD & SILVERSTAR GAS CONVECTION OVENS

TROUBLESHOOTING GUIDE

The left column of the following table lists symptoms that indicate a problem, while the center and right columns list the possible causes and appropriate corrective action. Note that the recommendations of this table assume that the wiring connections are good. When checking a component, always check the wiring attached to the component as well.

Symptom	Possible Cause	Check or Replace
Oven will not hold	Temperature probe not working.	Resistance across temperature probe leads at room temperature (70°F)
correct temperature.		should be approximately 1096 ohms.
	Temperature control not calling for heat.	When heat is required, there should be continuity between terminals 6
		and 7 on temperature control.
	Undersized gas supply line	Oven requires 3/4" ID gas line.
	Low gas pressure.	Oven requires 7" manifold water column pressure for natural gas, 11" for
		propane.
	Inadequate or improper ventilation.	Check ventilation hood. Verify draw and make up air adjustment.
	Out of calibration.	Calibrate according to procedure described on page 40.
Hot surface ignitor	No power to gas valve.	Check for 24V from ignition box to gas valve.
glows red but burners
	Faulty main gas solenoid.	Replace gas valve.
do not come on when
thermostat calls for heat	Faulty ignition module.	Replace ignition module.
(cooking light is on).
	Manual shutoff valve closed.	Open all shut-off valve.
	Manual valve on gas valve turned off.	Open manual valve on gas valve.
	Hot surface ignitor not in front of rear end	Re-position hot surface ignitor to be in front of rear end of burner.
	of burner.
Hot surface ignitor does	No power to ignitor.	Check that voltage from ignitor module to ignitor is 24V. Ignitor draws
not glow red.		approximately 3.35 amps at start as it heats up resistance goes down.
		Gas valve opens approximately 1.8 amps.
	Ignitor broken or cracked.	Should read continuity between leads on ignitor.
	No power or ignition module.	Should be 24V from transformer to ignition module.
	Check power to transformer.	Should be voltage stamped on serial plate. Check between 3 and 6 on
		terminal strip.
	Check blower motor. Motor should turn	Motor has centrifugal switch. Motor must be turning before ignition circuit
	when power switch is turned on and	is energized. Power for motors come through contactors. Check
	temperature control calls for heat.	contactors (one for high speed, one for low speed).
	Temperature control does not call for	Must read continuity between 6 and 7 on temperature control when
	heat.	calling for heat.
	No power out of power switch.	Check that unit power cord is plugged into power supply. Check switch
		for continuity when switch is closed.
First burner next to	Burners not aligned.	Check burner carry over wings for proper mating.
ignitor lights, but flame
	Burner and orifice out of alignment.	Orifice must inject gas down center of burner.
will not carry across to
other burners.	Gas pressure to low.	Oven requires 7" manifold water column pressure for natural gas, 11" for
		propane.
	Burner orifices clogged.	Make sure burner orifices are clear.

Table continues on next page.

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